Lumpy Oatmeal makes me Crazy!
If it is something that is going to be on your mind, maybe you need to ask her. Instead of looking to her, I would probably wonder about the motivation of the one who told you your past girlfriend.
It always hurts a bit to find out that people may have had an agenda in a relationship that we shared with them. But, it's kind of a life lesson. It happens - and you are no longer with that girl. So, while it hurts a bit, it's not much of an issue any longer.
As hard as it is, I'd just move forward and not take this too much to heart. Past is just that and your future is ahead of you. The lessons we learn guide us into that future and help determine what kind of people we wish to be. Concentrate on you and know that people like your ex-girlfriend (if she really did use you) may have a hard time finding their happiness.
We all walk our own road - don't let anyone else steer you from what you want and what kind of people you want to associate with.
Good luck - have a piece of chocolate, taste the good and don't let others get to you.